RESEARCHES ON IRRITABILITY 

 OF PLANTS 



CHAPTER I 



PLANT SCRIPTS 



Action of environment on plant — Revelation of internal condition by 

 character of response — Problems to be solved — Electrical response — 

 Mechanical response — Motile organ in Mimosa pudica — Response 

 in plant and animal — Different phases of the responsive move- 

 ment — Graphic record — Determination of absolute movement of 

 leaf and its time-relations — Characteristic effects of different 

 agencies on the response-curve — Specific difficulties in recording 

 plant-response. 



In strong contrast to the energetic animal, with its various 

 reflex movements and pulsating organs, stands the plant 

 in its apparent placidity and immobihty. Yet that same 

 environment, which with its changing influences so strikingly 

 affects the animal, is playing upon it also. Storm and 

 sunshine, the warmth of summer and the frost of winter, 

 drought and rain, all these and many more come and go 

 about it. What coercion do they exercise upon it ? What 

 subtle impress do they leave behind ? That they, in their 

 totahty, do leave the plant better or worse for their occur- 

 rence, we know. It is evident that internal changes are 

 effected by their agency which are entirely beyond our 

 visual scrutiny. Would it be possible to trace this general 

 action of the environment into some detail, and then follow 

 out the question of its particular effects upon the vegetal 

 organism ? Is there any means by which we might find out 



